Website login using C# to connect with existing sql server db

I'm a brand newbie...

I am attempting to log on to my website in VS2010, which connects to an existing SQL Server 2008 Express database through asp.net, utilizing C# as the code behind.

Here's my login.aspx.cs code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Net.Mail;
using System.Data.SqlClient;
using System.Web.Configuration;

public partial class Login : BasePage
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }

    protected void btnlogin_Click(object sender, EventArgs e)
    {
        int Results = 0;

        if (txtUsername.Text != string.Empty && txtPassword.Text != string.Empty)
        {

            Results = Validate_Login(txtUsername.Text.Trim(), txtPassword.Text.Trim());

            if (Results == 1)
            {
                lblMessage.Text = "Login is Good, Send user to another page or enable controls.";
            }
            else
            {
                lblMessage.Text = "Username or Password is incorrect.";
                lblMessage.ForeColor = System.Drawing.Color.Red;
            }
        }
        else
        {
            lblMessage.Text = "Please make sure that your username and password is correct.";
        }
    }

    protected int Validate_Login(String Username, String Password)
    {
        SqlConnection con = new SqlConnection(@"Server=MARIOM-PC\SQLEXPRESS;Database=Logon");

        SqlCommand cmdselect = new SqlCommand();

        cmdselect.CommandType = System.Data.CommandType.StoredProcedure;

        cmdselect.CommandText = "[dbo].[prcLoginv]";

        cmdselect.Parameters.Add("@Username", System.Data.SqlDbType.VarChar, 50).Value = Username;
        cmdselect.Parameters.Add("@Password", System.Data.SqlDbType.VarChar, 50).Value = Password;
        cmdselect.Parameters.Add("@OutRes", System.Data.SqlDbType.Int, 4);
        cmdselect.Parameters["@OutRes"].Direction = System.Data.ParameterDirection.Output;

        cmdselect.Connection = con;

        int Results = 0;

        try
        {
            con.Open();

            cmdselect.ExecuteNonQuery();

            Results = (int)cmdselect.Parameters["@OutRes"].Value;
        }
        catch (SqlException ex)
        {
            lblMessage.Text = ex.Message;
        }
        finally
        {
            cmdselect.Dispose();

            if (con != null)
            {
                con.Close();
            }
        }

        return Results;
    }
}

When I click my Log In button, it takes me to my C# code behind which should iterate through the btn_Login_Click, then the Validate_Login method. But then it does not correctly update my login page with the correct information. I always get the "incorrect password" error.

Please help!